If you have qemu installed (or in the SDK), you can start the image with:
cd path/to/image
./coreos_production_qemu_uefi.sh -curses
If you need to use a different ssh key or different ssh port:
./coreos_production_qemu_uefi.sh -a ~/.ssh/authorized_keys -p 2223 -- -curses
If you rather you can use the -nographic option instad of -curses. In this
mode you can switch from the vm to the qemu monitor console with: Ctrl-a c
See the qemu man page for more details on the monitor console.
SSH into that host with:
ssh 127.0.0.1 -p 2222